The overall goals of the Neuropathology Core (NPC) are to facilitate research, education and clinical care for clinicians, investigators, and family members by providing accurate and detailed neuropathologic assessment of tissues from subjects of interest, and by providing accurate and detailed neuropathologic assessment of tissues from subjects of interest, and by providing usable tissues from these subjects. These goals are met by standardized and thorough neuropathologic evaluation of brains from subjects enrolled by the Clinical Core, by providing investigators with well characterized tissue for research, and by advising investigators on use of post-mortem tissues. The Specific Aims of the NPC are to: (1) Expedite and standardize the collection and storage of fixed and frozen post-mortem CNS tissue from subjects followed in the MADRC Clinical Core; (2) Provide detailed, accurate, and standardized neuropathologic evaluation of harvested CNS tissue, and communicate this information to the MADRC database, investigators, clinicians and family members; (3) Provide samples of fixed or frozen CNS tissue from neuropathologically characterized cases to MADRC and other qualified investigators studying AD and other dementias. (4) Consult on the use of post-mortem material with investigators; (5) Train physicians, scientists, and other health care providers in the processing and evaluation of post-mortem CNS tissue. The NPC consists of a Brain Bank and a Histopathology Laboratory. Brain collection, detailed characterization, and provision of material is routine at the MADRC. A new initiative will be collection of brains from a prospectively followed group of elderly control subjects.